YELLOWING PAINT ON OR AROUND HEADLAMP DOORS (WHITE ONLY)

1988-89 Y-CAR

Some customers may comment regarding the yellowing of paint, on or around the headlamp doors on 1988 - 1989 Corvettes (WHITE PAINT ONLY). This condition is due to a reaction of the clear coat to some rubber components in the engine compartment.

IMPORTANT: 1. Vehicles with VINs after K5113927 are not affected with this condition.

2. Previously repaired vehicles can be identified by inspecting the underside of the inlet radiator hose for new part #10135650 molded into the hose, or a green band on the drive belt, new part #10105314.

To correct this condition, a new service kit, P/N 10105330, contains the following parts:

1 - Radiator hose, inlet 1 - A.I.R. hose, to ck. valve 1 - Radiator hose, outlet 1 - A.I.R. hose, to Cat. Conv. 1 - Heater hose, inlet 1 - A.I.R. hose, ck. valve/silen 1 - Heater hose, outlet 1 - A.I.R. hose, to ck. valve (less KC4) 1 - Heater hose, outlet 1 - Throttle Body coolant hose (with KC4) 1 - Belt, accessory drive

REPAIR PROCEDURE: (Use on vehicles with VINs prior to ---------------- J5120731).

1. Drain the cooling system and replace the radiator hoses, throttle body coolant hose, heater inlet hose and the heater outlet hose.

IMPORTANT: BOTH KC4 OPTION (ENGINE OIL COOLING SYSTEM) AND STANDARD HEATER OUTLET HOSES ARE INCLUDED IN THIS KIT. THE CORRECT HOSE USAGE WILL DEPEND ON THE VEHICLE OPTION CONTENT. SEE FIGURES 1 TO 4.

2. Replace all A.I.R. hoses included in the kit. See figures 5 and 6.

3. Replace the accessory drive belt and insure proper routing. Figure 7.

4. Remove and discard the hood support (gas tube). See Figure 8.

5. Make sure that when refilling the cooling system, the proper coolant refill procedure is used. Refer to Service Manual Section 6B.

6. Wash the engine, engine compartment and underside of the hood to remove any drive belt dust or rubber residues.

In addition to the installation of the kit, both headlamp doors should be replaced. New headlamp doors, P/N 10137733 (left) and 10137734 (right). (See Figure 9).

It may also be necessary to repaint the right side headlamp bezel only, if heavier yellowing conditions are present. See the PAINTING section described later in this bulletin.

WARRANTY INFORMATION: (For vehicles prior to VIN J5120731). -------------------- Use most applicable Labour operation from the Canadian Labour Time Guide and charge:

INCLUDES:

---------

Kit installation, remove and discard gas tube 1.6 hrs. Wash engine compartment and hood underside .3 hrs. Replace paint headlamp doors, paint bezel 2.0 hrs Material GD Rubbing/polishing OR spot/partial hood painting .5 hrs. Material GC Add of additional painting 1.3 hrs. Material GG Add for clear coat .2 hrs. Material CA

Time Allowance 4.4 Hours Total(Faint Yellowing) 5.9 Hours Total(Heavier Yellowing)

REPAIR PROCEDURE: (Use on vehicles with VINs after J5120731 ---------------- but prior to K5113927).

1. Install kit as previously described in steps 1 through 6.

2. Refer to the PAINTING section for determining the repairs for "FAINT" OR "HEAVIER" yellowing.

WARRANTY INFORMATION: (For vehicles after VIN J5120731 but prior -------------------- to VIN K5113927).

Use most applicable labour operation from the Canadian Labour Time Guide and charge:

INCLUDES:

-------- Kit installation, remove and discard gas tube 1.6 hrs. Wash engine compartment and hood underside .3 hrs. Rubbing/polishing OR spot/partial panel paint .5 hrs. Material GC Add for additional painting .8 hrs. Material GD Add for colour coat .2 hrs. Material CA

Time Allowance: 2.4 Hours Total (Faint Yellowing) 3.4 Hours Total (Heavier Yellowing)

PAINTING

Depending on the amount of the yellowing condition, a number of repairs are possible.

FAINT YELLOWING

1. Use wax and grease remover to remove dirt and grime from the yellowed area on the headlamp door or surrounding hood.

2. Polish the yellowed areas with 3M (R) Super Duty Rubbing Compound # 05955, or equivalent.

3. Follow step 2 using 3m (R) Finesse-it, #05928, or equivalent to remove swirl marks.

HEAVIER YELLOWING

More severe yellowing may require either "spot/partial panel repair" procedures. 0235b/16-18

General Motors bulletins are intended for use by professional technicians, not a "do-it-yourselfer". They are written to inform those technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions and know-how to do a job properly and safely. If a condition is described, do not assume that the bulletin applies to your vehicle, or that your vehicle will have that condition. See a General Motors dealer servicing your brand of General Motors vehicle for information on whether your vehicle may benefit from the information.